The subject of the invention is a conveying unit with a baffle, with a fuel pump arranged therein and with a filter which is arranged at the bottom of the baffle and which precedes an inlet orifice arranged at the bottom of the baffle. The conveying unit serves for the conveyance of fuel out of a fuel tank to an internal combustion engine of a motor vehicle.
It is known to use conveying units of this type in fuel tanks. Impurities contained in the fuel may enter the fuel pump and damage this. In order to protect the fuel pump from these impurities, the fuel sucked in by the fuel pump is filtered. For this purpose, the fuel pump is preceded by a coarse filter, in order to keep the particles which could result in damage to the fuel pump away from the suction-intake region of the fuel pump.
The filters known for this purpose are separate components which are mounted on the bottom of the baffle, so that, even when the filling level in the fuel tank is low, the filter is located in the fuel. An appropriately small mesh width of the filter fabric ensures that the entire surface of the filter is wetted with fuel, even when the filter penetrates only partially into the fuel. Since the filter is mounted under the bottom of the conveying unit, the construction space necessary in the axial direction for the conveying unit is increased to a considerable extent. Since present-day fuel tanks have an increasingly flatter configuration, there are growing problems in integrating conveying units of this type into the fuel tank.
It is known, further, to arrange shaped elements at the bottom of the baffle radially on the outside in the form of a ring, so that they stand up on the bottom of the fuel tank, in order to achieve a filter effect by means of the gaps which are formed between the shaped elements.
The object on which the present invention is based is, therefore, to provide a conveying unit with a baffle which requires as little construction space as possible along the axial extent and which ensures a reliable supply of the fuel to the inlet orifice of the baffle. Furthermore, the baffle of the conveying unit is to have as simple a construction as possible.